Optics of the Human Eye Experiment

“Optics of the Human Eye”

INTRODUCTION
The objectives of this experiment to investigate image formation in the human eye and determine how the visual defects of the eye is correct.
Theory
How Lenses Form Images
As light passing through different material, it refracts differently and moves with different speeds. Light enters the lens at the front surface and leaves at the back surface.
Lenses and Focal Length
In weak lenses, light intersects further away. So it is said long focal length. In strong lenses, light intersects at a short distance. So it is said short focal length. The amount by which light is bent is quantified by the lens’s focal length.
The principal focal length of a lens is determined by the index of refraction of the glass. Curvatures of its front and back, refraction of its material determine the focal length of a lens. We separate the lenses as convergent and divergent lenses. A divergent lens makes coming parallel lights spread and a convergent lens makes coming parallel lights come together. Below you can see the shapes of these lenses and how lights react when passing through them.

Figure 1

Image and Image Distance
In converging rays we see the real images. It is formed by the light passing through the lens. It can be seen directly. In diverging rays we see the virtual images which are formed by imaginary lines. It can’t be seen directly. You can see virtual image located at the point where the rays appear to be coming from.
The images which behind the lens are the real images and have positive image distance. The images which in front of the lens are the virtual images and have negative image distance.

Figure 2
Objects and the Object Distance

Objective
We will examine an eye model and study the visual problems.
Equipment List
Human Eye Model
Light